Flashcards
Week 5 -Fuzzy logic
Cards in this deck (16)
- 1Describe fuzzy systems.-Originated because the real, analogue world has not absolutes.
-Gradual transition from one state or condition to another.
-Computers can only deal wth crisp data. - 2Describe difference between crisp data and fuzzy logic data-Crisp data can only be 1 or 0, True or False.
-Fuzzy logic is fluid, i.e can be 0.5 or 0.75. - 3Name fuzzy logic applications-Engine management, Anti-lock breaks.
-Transmission control, Blast furnace control.
-Image/pattern recognition, planning and scheduling.
-Air condition, Wasing machines, Video cameras. - 4Advantages of using fuzzy systems-Thier operation reflects the way a human would control the system.
-Alleviates need for detailed mathematical model of system. - 5Equation for Boolean relationship of a crisp setMewA (x) = 0 if not a member of set A
1 if memeber of set A - 6Describe the similaritites of fuzzy reasoning to expert systems.-Structured around a knowledge base.
- Around a set of fuzzy rules .
-Similar "IF...THEN" structure.
-But rules contain fuzzy properties. - 7Define Defuzzification-Converts fuzzy ouputs to crisp values.
- 8Name 3 mothods of defuzzification-Mean of maxima.
-Centre of maxima.
-Centr of gravity (Centroid). - 9Describe the steps of calculatiing the mean of maxima-Identify the limits of the fuzzy output whare are at the maximum values.
-The mean value of these limits becomes the crisp value. - 10Mean of maxima equationCrisp output = (Smax + Smin) / 2
- 11Describe the steps to calculate the centr of maxima-Used when the fuzzy output has a number of levels.
-Highest and next highest plateau are identified.
- Crisp ouput is the midpoint between the centres of the two plateau. - 12Describe the steps to calculate the centr of maxima-Step 1: Find the crisp output of one level using the mean of maxima equation.
-Step 2: Do the same for the next highest level.
-Step 3: Using the same equation use the two crisp outputs as Smax and Smin. - 13Describe the steps for calculating the centre of gravity (centroid)- First moment of area is used to find the centroid of the fuzzy output.
- This gives the crisp output. - 14Equation for centr of gravityCrisp Output = E (moments of individual areas) / Total area under curve
- 15Describe Fuzzy State Machine- Extension to standard state machines.
-instead of processing crisp symbols both inputs and outputs are fuzzy values. - 16Advantages of Fuzzy state machines- Smooth control and reasoning with degrees of truths which proves more humanlike.
-Internally each state can be defined as a variable too.
-Good for caputring emotions as they are not discrete.
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- Flashcards on Week 5 -Fuzzy logic, created by Kevin Conaghan on 06/05/2018.
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- Kevin Conaghan
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